Vinylidene-terminated polydienes are known in the art. For example, U.S. Pat. No. 3,652,520 teaches preparation of polymerizable polydiene ethylenically-unsaturated esters having at least about one terminal ethylenically unsaturated acyloxy group by esterifying intermediate polyhydroxy polydienes with an unsaturated acyl compound. The vinylidene-terminated polydienes can be used together with certain other materials (e.g., reactive vinyl comonomers as taught by U.S. Pat. No. 3,652,520) as caulks, sealants, or the like, but addition of catalyst and/or crosslinking agents is generally required. An example of a known vinylidene-terminated liquid polymer having a polyether backbone is the diacrylate ester of the diglycidyl ether of bisphenol A. New caulks and sealants are desired which contain vinylidene-terminated polymers and which cure readily at room temperature without addition of catalysts or crosslinking agents.